This invention relates to a therapeutic method of treating the chronic human superficial fungus infection tinea pedis produced by the pathogenic dermatophytic fungi Microsporum sp., Trichopyton sp., and Epidermophyton sp., which invade and attack keratinized skin areas of the body, by repeatedly applying topically to the itching, macerated, cracked, and scaling skin areas of the body at the site of the infection a fungicidally effective amount of a lotion antagonistic to the dermatophytic fungi in order to exert at least an inhibitory growth effect upon the dermatophytes, the lotion including an antimicrobially active silane which is a quaternary ammonium salt.
Antimicrobial agents are chemical compositions that are used to prevent microbiological contamination and deterioration of products, materials, and systems. Particular areas of application of antimicrobial agents and compositions are, for example, cosmetics, disinfectants, sanitizers, wood preservation, food, animal feed, cooling water, metalworking fluids, hospital and medical uses, plastics and resins, petroleum, pulp and paper, textiles, latex, adhesives, leather and hides, and paint slurries. Of the diverse categories of antimicrobial agents and compositions, quaternary ammonium compounds represent one of the largest of the classes of antimicrobial agents in use. At low concentrations, quaternary ammonium type antimicrobial agents are bacteriostatic, fungistatic, algistatic, sporostatic, and tuberculostatic. At medium concentrations they are bactericidal, fungicidal, algicidal, and viricidal against lipophilic viruses. Non-silicone quaternary antimicrobials are not known to be or taught to be effective against dermatophytic fungi and in fact are known not to be effective in such uses because of interferences caused by the organic matter present on skin specifically the active infection sites. Silicone quaternary ammonium salt compounds are well known as exemplified by U.S. Pat. No. 3,560,385, issued Feb. 2, 1971, and the use of such compounds as antimicrobial agents is taught, for example, in a wide variety of patents such as U.S. Pat. No. 3,730,701, issued May 1, 1973, and 3,817,739, issued June 18, 1974, where the compounds are used to inhibit algae; 3,794,736, issued Feb. 26, 1974, and 3,860,709, issued Jan. 14, 1975, where they are employed for sterilizing or disinfecting a variety of surfaces and instruments; 3,865,728, issued Feb. 11, 1975, where the compounds are used to treat aquarium filters; 4,259,103, issued Mar. 31, 1981; and in British Pat. No. 1,386,876, of Mar. 12, 1975. Published unexamined European application No. 228464 of July 15, 1987, teaches the microorganisms on plants can be killed by the application thereto of an aqueous mixture of a surfactant and an organosilicon quaternary ammonium compound. In a particular application of an antimicrobial silicone quaternary ammonium compound, a paper substrate is rendered resistant to the growth of microorganisms in U.S. Pat. No. 4,282,366, issued Aug. 4, 1981. In U.S. Pat. No. 4,504,541, issued Mar. 12, 1985, an antimicrobial fabric is disclosed which is resistant to discoloration and yellowing by treatment of the fabric with a quaternary ammonium base containing an organosilicone. U.S. Pat. No. 4,615,937, issued Oct. 7, 1986, as well as its companion U.S. Pat. No. 4,692,374, issued Sept. 8, 1987, relate to wet wiper towelettes having an antimicrobial agent substantive to the fibers of the web and being an organosilicon quaternary ammonium compound. In a series of Burlington Industries, Inc. U.S. Pat. Nos. 4,408,996, issued Oct. 11, 1983, 4,414,268, issued Nov. 8, 1983, 4,425,372, issued Jan. 10, 1984, and 4,395,454, issued July 26, 1983, such compounds are disclosed to be useful in surgical drapes, dressings, and bandages. This same assignee also discloses these compounds as being employed in surgeons' gowns in U.S. Pat. Nos. 4,411,928, issued Oct. 25, 1983, and 4,467,013, issued Aug. 21, 1984. Organosilicon quaternary ammonium compounds have been employed in carpets, in U.S. Pat. No. 4,371,577, issued Feb. 1, 1983; applied to walls, added to paints, and sprayed into shoes, in U.S. Pat. No. 4,394,378, issued July 19, 1983; applied to polyethylene surfaces and used in pillow ticking in U.S. Pat. No. 4,721,511, issued Jan. 26, 1988; in flexible polyurethane foams of fine-celled, soft, resilient articles of manufacture in U.S. Pat. No. 4,631,297, issued Dec. 23, 1986; and mixed with a surfactant in Japanese Kokai application No. 58-156809, filed Aug. 26, 1983, of Sanyo Chemical Industries, Ltd., for the purpose of achieving uniformity of distribution of the compounds to a surface. Thus, the versatility of such compositions is readily apparent. However, no one, as far as is known, has used an organosilicon quaternary ammonium compound in lotion form in order to provide a topical skin application for the treatment of diseases such as tinea pedis. This infection has typically been treated with such compositions as morpholine hydroperfiodide as evidenced by U.S. Pat. No. 2,290,710; griseofulyin antifungous antibiotic drug; and a combination of undecylenic acid and zinc undecylenate. Therefore, in accordance with the present invention, it has been found that compositions which are antimicrobial can be formed in soothing lotion form and since they possess the characteristics and advantages of the silicone quaternary ammonium salts can be used to effectively treat skin infections such as tinea pedis. It has been further shown that substrates treated with organosilicon quaternary ammonium compounds provide for protection against organisms known to cause tinea pedis, tinea corpus and tinea captis. Thus, the compositions of the present invention act in preventing microbiological contamination and deterioration. For example, 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride, hereinafter referred to as TMS, is an effective antimicrobial agent in which the active ingredient reacts with substrates with which it is brought into contact. These substrates demonstrate nonleaching broad spectrum antimicrobial activity. By including an antimicrobial component in the lotion composition, a convenient delivery system is realized. Hence, the compositions set forth in the present invention possess unique features and advantages over existing antimicrobial treating agents and provide improved results thereover. Thus, the disadvantages of the prior art are overcome with the present invention wherein improved antimicrobial agents are provided.